Lipitor is used to reduce the amounts of LDL (bad) cholesterol, total cholesterol, triglycerides (another type of fat), and apolipoprotein B (a protein needed to make cholesterol) in your blood. Lipitor is also used to increase the level of HDL (good) cholesterol in your blood. These actions are important in reducing the risk of hardening of the arteries, which can lead to heart attacks, stroke, and peripheral vascular disease.